Preferred orientations of evaporated Ni films on Mo and SiO₂ substrates

Nickel films have been prepared by electron beam evaporation under UHV conditions on molybdenum and silica substrates, at different temperatures between Zone I and the Zone II-III transition, and their textures have been studied using the energy dispersive X-ray diffraction technique with synchrotron radiation. At room temperature the effect of the substrate is slight and the main features of the films on both substrates are mixed (111) and (002) fibre texture, believed to represent nucleation-dominated texture. At Zone II temperatures, nickel films on molybdenum substrates show a (001)[100] sheet texture that mirrors the (001)[110] sheet texture of the molybdenum substrates, and is ascribed to anisotropy of interfacial energy. Films on silica substrates are dominated by the (111) fibre texture, ascribed to grain growth driven by surface energy minimisation, and become more purely (111) orientated with increasing temperature. Results also show that the tendency for nickel films on silica substrate to form (111) fibre texture is lowest near the Zone I-II transition temperature, where the (002) component is strongest. This tendency is discussed in terms of the models of Walton and of Lee.